Self-Assembled Triphenylphosphonium-Conjugated Dicyanostilbene Nanoparticles and Their Fluorescence Probes for Reactive Oxygen Species.

We report self-assembled novel triphenylphosphonium-conjugated dicyanostilbene-based as selective fluorescence turn-on probes for ¹O₂ and ClO. Mono- or di-triphenylphosphonium-conjugated dicyanostilbene derivatives and formed spherical structures with diameters of ca. 27 and 56.5 nm, respectively, through π-π interaction between dicyanostilbene groups. Self-assembled showed strong fluorescent emission upon the addition of ¹O₂ and ClO compared to other ROS (O₂, OH, NO, TBHP, H₂O₂, GSH), metal ions (K⁺, Na⁺), and amino acids (cysteine and histidine). Upon addition of ¹O₂ and ClO, the spherical structure of changed to a fiber structure (8-nm wide; 300-nm long). Upon addition of ¹O₂ and ClO, the chemical structural conversion of was determined by FAB-Mass, NMR, IR and Zeta potential analysis, and the strong emission of the self-assembled was due to an aggregation-induced emission enhancement. This self-assembled material was the first for selective ROS as a fluorescence turn-on probe. Thus, a nanostructure change-derived turn-on sensing strategy for ¹O₂ or ClO may offer a new approach to developing methods for specific guest molecules in biological and environmental subjects.